Page restore is a technique used to replace corrupted pages of information in a database with uncorrupted data from a backup. Page-level restore can be performed via SSMS or T-SQL. The intent of the restore is to fix one or more corrupted pages from the available backups.
What is page level in SQL?
The fundamental unit of data storage in SQL Server is the page. The disk space allocated to a data file (. mdf or . ndf) in a database is logically divided into pages numbered contiguously from 0 to n. Disk I/O operations are performed at the page level.
What is meant by restore pages?
The goal of a page restore is to restore one or more damaged pages without restoring the whole database. Typically, pages that are candidates for restore have been marked as “suspect” because of an error that is encountered when accessing the page.
What is online page and restore?
During an online file restore, any file being restored and its filegroup are offline. If any of these files is online when an online restore starts, the first restore statement takes the filegroup of the file offline. In contrast, during an online page restore, only the page is offline.
How do I fix page level corruption in SQL Server?
Fixing SQL Database Page-Level Corruption
- Use a text comparison tool to check the differences between the original file and the corrupted file.
- On the corrupted file, run the DBCC CHECKDB command. …
- To examine the contents of the infected page, run the DBCC PAGE command.
What does Page mean in database?
A page is a unit of storage whose size is configurable on a system-wide, database-wide, or conglomerate-specific basis. By default, a conglomerate grows one page at a time until eight pages of user data (or nine pages of total disk use, which includes one page of internal information) have been allocated.
What is IAM page in SQL Server?
Summary. SQL Server uses index allocation maps to track which pages have been allocated to which allocation unit. They are stored in special IAM pages. Each IAM page covers an area of 64000 extents in a file, a so-called GAM-interval.
What happens when you restore data?
Data restore is the process of copying backup data from secondary storage and restoring it to its original location or a new location. A restore is performed to return data that has been lost, stolen or damaged to its original condition or to move data to a new location.
What is the purpose of backup and restore?
Backup and restore refers to technologies and practices for making periodic copies of data and applications to a separate, secondary device and then using those copies to recover the data and applications—and the business operations on which they depend—in the event that the original data and applications are lost or …
What is restore database in SQL Server?
Restoring is the process of copying data from a backup and applying logged transactions to the data. Restore is what you do with backups. Take the backup file and turn it back into a database.
Do I need to take database offline to restore?
We Recommend to Take active Databases Offline before restoring over them.
How do I get my database online from restoring mode?
Right-click the database, go to Tasks->Restore->Transaction Logs 2. Find the backup file that was used for the Tail Log back up 3. Restore the backup The restore should succeed and bring the database back online.
How do I move a database from SQL recovery to online?
If the database is in restoring state run the command below to bring the database online:
- RESTORE DATABASE <Database Name> WITH RECOVERY.
- Step 01: Disconnect all the connections to the database. USE master. …
- Step 02: Bring the database online. RESTORE DATABASE <Database Name> WITH RECOVERY.
How do I fix suspect pages in SQL Server?
Using SQL Server Management Studio
Expand System Databases, expand msdb, expand Tables, and then expand System Tables. Expand dbo. suspect_pages and right-click Edit Top 200 Rows. In the query window, edit, update, or delete the rows that you want.
How can check corrupted table in SQL Server?
First, enable it by going to the database and choosing Properties from the right-click menu. Go to Recovery option, Choose Page Verify, and write CHECKSUM. Then Choose the Target Recovery Time in Seconds and click OK. The modern SQL Server versions enable the verify with CHECKSUM by default.
What is online index in SQL Server?
The ONLINE option allows concurrent user access to the underlying table or clustered index data and any associated nonclustered indexes during these index operations. For example, while a clustered index is being rebuilt by one user, that user and others can continue to update and query the underlying data.